In building construction, different types of panels for forming interior walls, exterior walls and ceilings are used. Typically, panels (also referred to as boards) are affixed to framing members also known as studs such as in balloon framing arrangements.
Often used in construction of interior walls, is a gypsum board faced with paper. Typically, this board (also referred to as wallboard or drywall) is made by preparing a slurry comprising calcined gypsum, water and other components. The gypsum slurry is then sandwiched between two sheets of paper, forming a gypsum core between two paper cover sheets. The gypsum core is then allowed to set. U.S. Pat. Nos. 8,197,952, 4,853,085, and 1,769,519 assigned to United States Gypsum Company, provide gypsum wallboard and methods of making it.
One of the requirements for gypsum wallboard is to provide an acoustic barrier between two adjacent rooms, including in multi-unit dwellings such as apartment buildings and hotels, and dwellings located next to a commercial building or an airport.
As wallboards differ in their compositions, so does their ability to provide an acoustical barrier. Accordingly, wallboards are classified based to their ability to diminish (dampen) sound transmission through a wall. This wallboard characteristic is known as Sound Transmission Class (STC) which can be measured for each wallboard according to ASTM standard method E90 “Standard Test Method Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements.”
ASTM E413 “Classification for Sound Insulation” can be used to calculate a STC rating for a particular wallboard structure. The higher is the STC value of a particular wallboard, the better this wallboard is at absorbing noise. Building construction codes may require wallboard with a certain minimum STC value for each particular application.
One strategy for obtaining a wallboard with a high STC value is to produce wallboard with dense gypsum core. While this method may improve the acoustical properties of wallboard, it also produces wallboard which is heavy, while lighter wallboard would be a better solution for improved job site efficiency.
Another strategy is to laminate two gypsum boards together or to create a multilayer structure. U.S. Pat. No. 7,799,410 discloses a laminated panel in which two different layers are glued together. However, laminated boards are extremely difficult to process for scoring which may result in lower productivity and decreased job site efficiency.
It would be advantageous to have a method by which the same basic wallboard can be customized for different purposes with respect to sound absorption.